The Center for Clinical Epidemiology and Biostatistics (CCEB) and the Abramson Cancer Center of the University of Pennsylvania (Penn), an NCI-designated Comprehensive Cancer Center, both of which are based in Penn's School of Medicine (SOM), propose to continue an innovative, rigorous, and successful two to three-year training program for clinical investigators in cancer clinical epidemiology. The mission of the Cancer Clinical Epidemiology Training Program is to prepare individuals, either clinicians who have completed clinical training in a relevant medical specialty for PhD epidemiologists, for successful careers as independent clinical investigators capable of using the range of approaches available in epidemiology and biostatistics to address research issues of public health importance to the development or treatment of cancer, including etiology, prognosis, prevention and early detection, treatment, clinical economics, technology assessment, medical decision making, and quality of patient care. The Specific Aims of the training program are to: (1) provide in-depth knowledge of the research techniques appropriate for clinical cancer research;(2) provide opportunities for the clinical study of topics related to cancer;(3) provide intensive, supervised research experiences with mentors in clinical epidemiology and cancer research;and (4) bring together faculty and trainees through participation in seminar series and workshops offered through the CCEB and the Abramson Cancer Center. Most trainees matriculate in the Master of Science in Clinical Epidemiology (MSCE) degree program. The two- to three year training program consist of: (1) a core curriculum of required and elective courses in clinical epidemiology, research methodology, and biostatistics;(2) an elective course in cancer epidemiology;(3) extensive independent readings;(4) attendance and participation in research seminars and workshops at the CCEB and the Abramson Cancer Center;(5) instruction in the responsible conduct of research and regulatory affairs;and (6) the development and completion of a mentored independent research project in cancer. Strengths of the proposed program are: (1) the long history of successful research training programs in the CCEB and Abramson Cancer Center, including the success of the Cancer Clinical Epidemiology Training Program;(2) the comprehensive course offerings and research programs available to trainees;(3) a history of collaborative links already forged between the CCEB and the Abramson Cancer Center;and (4) the extensive successful training records of the program directors and faculty. In addition, the availability of resources such as excellent basic and translational laboratories in the Abramson Cancer Center, the broad range of rich expertise of the faculty in the CCEB and Abramson Cancer Center, numerous existing large databases available to these groups that can be used for research projects and training, a broad array of specialized analytic capabilities available for clinical studies (e.g., clinical trials, case-control, cohort research, etc.), and the faculty members'commitment to collaborative research and training, combine to provide an ideal environment for the continuation of this training program.